> ## Documentation Index
> Fetch the complete documentation index at: https://docs.automate.ax/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Automate.ax automations are TypeScript programs.
> Use Bun for installation and command examples.
> Use Automate.ax for the product name and automate.ax for the package, CLI, and domain.
> Treat documented public APIs as current; do not invent transitional or deprecated names.

# On card commented

> Start an automation when a comment is added to a Trello card.

`onTrelloCardCommented` matches Trello `commentCard` actions on one board.

```ts automations/watch-trello-comments.automation.ts theme={null}
import { automation } from "automate.ax"
import { onTrelloCardCommented } from "automate.ax/trello"

export default automation("Watch Trello comments", () => {
  onTrelloCardCommented({ board: "board-id" })
})
```

`board` is required and accepts an ID, short link, or URL. Optional static `account` defaults to the project binding.

Returns a normalized card-event signal with `commentText` plus action metadata, board and card references, optional list, and optional creator. `commentText` is optional at the type level because Trello webhook fields can be absent; use [List comments](/reference/integrations/trello/actions/list-comments) when you need the normalized comment object and creation time.